[The study of aluminium diffuser calibration in the UV]

Area of Science:

• Optics and Photonics
• Materials Science

Context:

• Established a novel measurement setup for bi-directional reflectance distribution function (BRDF) in the ultraviolet (UV) spectral range.
• Characterized aluminum diffusers, crucial components in optical systems requiring stable UV reflectance.
• Achieved high relative accuracy in BRDF measurements, exceeding 2.5%.

Purpose:

• To establish and validate a BRDF measurement system for UV applications.
• To quantify the hemispheric reflectance of aluminum diffusers across a broad UV-Vis spectrum (250-650 nm).
• To investigate the temporal stability and degradation of diffuser reflectance over approximately one year.

Summary:

• The study details the successful establishment of a UV BRDF measurement setup with high accuracy.
• Hemispheric reflectance of aluminum diffusers was measured, showing an increase with wavelength (approx. 6% change from 300-360 nm).
• Significant temporal degradation of reflectance was observed, with peak decreases up to 2.6% in the 250-300 nm range.

Impact:

• Provides a reliable method for characterizing UV optical materials.
• Highlights the importance of considering material degradation in UV optical system design.
• Offers quantitative data on aluminum diffuser performance and aging, crucial for long-term UV applications.